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Chemistry of Life

Life Chemistry of

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Page 1: Life Chemistry of

Chemistry of Life

Page 2: Life Chemistry of

Atoms- The basic unit of matter is called an Atom

- Atoms are incredibly small, but despite its extremely

small size, an atom contains subatomic particles that

are even smaller

- Three subatomic particles:

- Proton - Neutron

- Electron

Page 3: Life Chemistry of

AtomsParticle Charge Location in Atom

Proton Positive (+) Nucleus

Neutron Neutral (0) Nucleus

Electron Negative (-) Constant motion

surrounding the nucleus

Page 4: Life Chemistry of

Atoms- Nucleus:

- Center of the atom that

contains the protons and neutrons

- Electrons move around the nucleus

in orbitals

- Atoms are neutral even with the charged

particles because it has an equal number of

both electrons (-) & Protons (+)

Page 5: Life Chemistry of

Elements - Element:

- Pure substance that consists entirely

of one type of atom

- More than 100 elements are known, but

only about two dozen are commonly found

in living organisms- Elements are represented by a one- or two-letter

symbol

Page 6: Life Chemistry of

Elements - The number of

protons in an

atom of an

element is the

element's

atomic number

Page 7: Life Chemistry of

Chemical Compounds - Chemical Compound/Molecule:

- substance formed by the chemical combination of

two or more elements in definite proportions

- In nature, most elements are found combined with

other elements in compounds

- Scientists show the composition of compounds by a

kind of shorthand known as a chemical formula.

Page 8: Life Chemistry of

Chemical Compounds - Water, H

2O (Chemical Formula)

Contains two atoms of hydrogen for each atom of

oxygen

- Table Salt: NaCl (Chemical Formula) 1:1 Ratio

- Hydrogen Peroxide: H2

O2

(Chemical Formula)

- Carbon Dioxide: CO2

(Chemical Formula)

Page 9: Life Chemistry of

Chemical Bonds - Chemical Bonds:

- link that holds together atoms in compounds

- Bond formation involves the electrons that surround

each atomic nucleus

- The main types of chemical bonds are ionic bonds and

covalent bonds

Page 10: Life Chemistry of

Chemical Bonds

- Ions are positively and negatively charged atoms

Think of the MVP Award: One player gets the trophy

- Ionic Bond:

formed when one or more electrons

are transferred from one atom to another

- Strong attraction between oppositely charged ions, a

positive ion and a negative ion come together

Page 11: Life Chemistry of

Chemical Bonds - Sodium (Symbol Na) is a chemical element.

Chlorine (Symbol Cl) is a chemical element.

- When 1 sodium atom & 1 chlorine atom bond together

(Symbol NaCl) they form the compound Sodium Chloride

- This is commonly known as Table Salt

Page 12: Life Chemistry of

Chemical Bonds

11 Electrons 17 Electrons

Page 13: Life Chemistry of

Chemical Bonds - The valence electron is transferred from sodium to

chlorine.

- Sodium now becomes a Sodium Ion (Na+)

- Chlorine is now negative and is a Chlorine Ion (Cl-)

- Sodium Chloride is held together by “OPPOSITES

ATTRACT”, the attraction between a Sodium Ion (Na+)

and Chlorine Ion (Cl-)

Page 14: Life Chemistry of

Chemical Bonds

Page 15: Life Chemistry of

Chemical Bonds

- These bonds very strong and usually do not break

easily

Think of CO-MVP Award: Both are trying to take it

- It means that the moving electrons actually travel in

the orbitals of both atoms

- Covalent Bond:

- forms when electrons are shared

between atoms

Page 16: Life Chemistry of

Chemical Bonds

- When 2 hydrogen atoms and 1 oxygen atom bond

together (Symbol H2O) they form the compound

commonly known as water

- Hydrogen (Symbol H) is a chemical element

Oxygen (Symbol O) is a chemical element

Page 17: Life Chemistry of

Chemical Bonds

1 Electron Each

8 Electrons

Page 18: Life Chemistry of

Chemical Bonds - The valence electrons are shared between the 2

hydrogen and oxygen atoms

- The electron orbitals actually overlap so that the

shared valence electrons fly around the nuclei of all 3

atoms.- This is an example of a covalent bond.

Page 19: Life Chemistry of

Chemical Bonds

Covalent Bond

Water

Page 20: Life Chemistry of

Let’s stop & Think:Out of the two bonds, which type of bond is stronger, ionic or covalent?

Any idea why?

Page 21: Life Chemistry of

Journal Entry

Page 22: Life Chemistry of

Water- Water is the single most abundant compound in most

living things

- Water covers three fourths of Earth's surface

- Water is one of the few compounds that is a liquid at

the temperatures found over much of Earth's surface

Page 23: Life Chemistry of

Water- Unlike most substances, water expands as it freezes

- Ice is less dense than liquid water, which explains why

ice floats on the surface of lakes and rivers

- Water is found on earth in all 3 phases

- Solid - Gas

- Liquid

Page 24: Life Chemistry of

Water- Water is a neutral molecule

- The positive charges on its 10 protons balance out the

negative charges on its 10 electrons

- Water (H2

O)

Oxygen has 8 protons

Hydrogen has 1 proton

Page 25: Life Chemistry of

Water- With 8 protons in its nucleus, an oxygen atom has a

much stronger attraction for electrons than does the

hydrogen atom with a single proton in its nucleus

- At any moment, there is a

greater probability of

finding the shared electrons

near the oxygen atom than

near the hydrogen atom

Page 26: Life Chemistry of

Water- Water has a bent shape

- Therefore the oxygen atom is on one end of the

molecule and the hydrogen atoms are on the other

Page 27: Life Chemistry of

Water- Oxygen’s larger size & greater attraction for electrons

causes the Oxygen side of the water molecule to have a

slightly negative charge

- Hydrogen atoms will have

a slightly positive charge

Page 28: Life Chemistry of

Water- Polar molecule:

- A molecule in which the

charges are unevenly

distributed

- A water molecule is polar because there is an uneven

distribution of charge between the slightly positive

Hydrogen atoms & the slightly negative oxygen atoms

Page 29: Life Chemistry of

Hydrogen Bonds- Because of its polarity, water molecules form hydrogen

bonds with other water molecules

- Polar molecules have a very strong attraction toward

one another

- The attraction between the hydrogen atom on one

water molecule and the oxygen atom on another water

molecule is an example of a hydrogen bond

Page 30: Life Chemistry of

Hydrogen Bonds- Hydrogen bonds are the bonds which hold individual

water molecules together

- Hydrogen bonds are not as strong as covalent or ionic

bonds

- Water's ability to form multiple hydrogen bonds is

responsible for many of its special properties

Page 31: Life Chemistry of

Draw MULTIPLE hydrogen bonds between several water molecules

Page 32: Life Chemistry of

Hydrogen Bonds- Cohesion:

- an attraction between same molecules (substance)- Due to surface tension, insects and spiders can walk on

a pond's surface. They do not weigh enough to break the

hydrogen bonds at the surface- Cohesion causes molecules to draw

inward at surface

Page 33: Life Chemistry of

Hydrogen Bonds- Adhesion

- an attraction between molecules of

different substances

- Adhesion causes water to bend at surface

- It’s the ability of water molecules to

stick to other materials

Page 34: Life Chemistry of

Hydrogen Bonds- Adhesion between water and

glass also causes water to rise in a

narrow tube against the force of

gravity

- Capillary action is one of the

forces that draw water out of the

roots of a plant and up into its

stems and leaves.

Page 35: Life Chemistry of

Solutions & Suspensions - Water is not always pure—it is often found as part of a

mixture

- Mixture:

- a material composed of two or more elements or

compounds that are physically mixed together but not

chemically combined.- Example: Salt and pepper Sugar and Sand

Page 36: Life Chemistry of

Solutions & Suspensions - Two types of mixtures that can be made with water are

solutions and suspensions

- Solution:

- mixture of two or more substances in which the

molecules of the substances are evenly distributed- Example: Salt & Water

Page 37: Life Chemistry of

Solutions & Suspensions - The salt & chloride (NaCl: Table Salt) ions gradually

become dispersed in the water

- Solute:

- Substance that gets dissolved in a solution

Example: Salt- Solvent: The substance in which the solute dissolves in

Example: Water

Page 38: Life Chemistry of

Solutions & Suspensions - Water's polarity gives it the ability to dissolve both

ionic compounds and other polar molecules

- Without exaggeration, water is the greatest solvent on

Earth

Page 39: Life Chemistry of

How does NaCl dissolve in water?

The positive hydrogen of H2O attracts the Cl- ion and the negative oxygen of H2O attracts the Na+ ion. Water literally pulls NaCl apart

Page 40: Life Chemistry of

Solutions & Suspensions - Some materials do not dissolve when placed in water

but separate into pieces so small that they do not settle

out- Suspensions:

- A mixture of water and nondissolved materials

Example: blood, milk, oil in water, mud in water

Page 41: Life Chemistry of

Solutions & Suspensions - Are the following Solutions or Suspensions:

Salt and Water Orange Juice with Pulp

Sand and Water

Milk Blood

Kool-Aid

Chicken Noodle Soup Coffee

Salad dressing

Solution

Suspension

Suspension

Solution

Suspension

Solution

Suspension

Suspension

Solution

Page 42: Life Chemistry of

Properties of Water Lab

Page 43: Life Chemistry of

Why does water sit on the rim of the beaker without dripping off?

Page 44: Life Chemistry of

Why does the paperclip float?

Page 45: Life Chemistry of

Why did the cotton absorb the water?

Page 46: Life Chemistry of

Why did the cotton eventually sink?

Page 47: Life Chemistry of

Acids, Bases, and pH- A water molecule can react to form ions

- Because the number of positive hydrogen ions

produced is equal to the number of negative hydroxide

ions produced, water is neutral

Page 48: Life Chemistry of

Acids, Bases, and pH- pH:

- measurement system used to indicate the

concentration of hydrogen ions (H+) in solution; ranges

from 0 to 14

- At a pH of 7, the concentration of H+ ions and OH−

ions is equal

Page 49: Life Chemistry of

Acids, Bases, and pH- Acidic:

- Solutions with a pH below 7

- They have more H+ ions than OH− ions

- Strong acids tend to have pH values that range from 1

to 3

Page 50: Life Chemistry of

Acids, Bases, and pH- Basic:

- Solutions with a pH above 7

- They have more OH− ions than H+ ions

- Strong bases, such as lye, tend to have pH values

ranging from 11 to 14

Page 51: Life Chemistry of

Acids, Bases, and pHType of Ions pH Examples Characteristics

Acids H+ 1-7 Lemon, vinegar, soda, aspirin

Sour, burns, dissolves things

Neutrals H2O 7 Pure Water Not acidic, not basic!

Bases OH- 7-14 Soap, baking soda, ammonia

Bitter, slippery

Page 52: Life Chemistry of

Acids, Bases, and pH- Drawing: How would a basic solution differ from an

acidic solution?

Page 53: Life Chemistry of

Acids, Bases, and pH- Drawing: What happens

when you mix an Acid &

Base solution?

Page 54: Life Chemistry of

Acids, Bases, and pH- Buffers

- weak acids or bases that react with strong acids and

bases to prevent sharp changes in pH

- Buffers are so important:

When acids and bases are added to the body, the

blood “buffers” prevent a drastic pH change

Page 55: Life Chemistry of

Acids, Bases, and pH- Buffers help to neutralize pH

- Buffers help control pH in blood, etc

- The pH of the fluids within most cells in the human

body must generally be kept between 6.5 and 7.5.

- If the pH is lower or higher, it will affect the chemical

reactions that take place within the cells

Helps with maintaining homeostasis

Page 56: Life Chemistry of

Solutions & Suspensions

Page 57: Life Chemistry of

Journal Entry

Page 58: Life Chemistry of

Macromolecule Jigsaw & Concept Map

Page 59: Life Chemistry of

Chemical Reactions- Chemical Reactions:

- Process that transforms one set of compounds into

another

- Some reactions occur very quickly, while others occur

extremely slowly

- Anything your body does involves a chemical reaction

Page 60: Life Chemistry of

Chemical Reactions- How do you know when a chemical reaction has

occurred:- Change in temperature (products feel cold or hot)

- Change in color

- Formation of a solid

- Formation of a gas – bubbles!

- Giving off light

Page 61: Life Chemistry of

Chemical Reactions- Chemical reactions are a change from an initial set of

molecules to another set of molecules through the

breaking of bonds and formation of new bonds

- Reactants:

- The elements or compounds that enter into a

chemical reaction

- Starting substances (left side) of a chemical equation

Page 62: Life Chemistry of

Chemical Reactions- Products:

- The elements or compounds produced by a chemical

reaction- Substances formed (right side) of a chemical equation

Page 63: Life Chemistry of

Chemical Equations- How to write a chemical reaction

- Reactants + Reactant → Product + Product

- Real Life Example:

carbon dioxide + water → glucose + oxygen

- Chemical Reaction:

CO2

+ H2

O → C6

H12

O6

+ O2

Page 64: Life Chemistry of

Chemical Equations- Chemical Reaction:

CO2

+ H2

O → C6

H12

O6

+ O2

Reactants

Products

Page 65: Life Chemistry of

Chemical Equations- Chemical Reaction:

CO2

+ H2

O → H2

CO3

Reactants

Products

Page 66: Life Chemistry of

Energy in Reactions- Energy is released or absorbed whenever chemical

bonds form or are broken

- Some chemical reactions release energy, and other

reactions absorb energy

- Energy changes are one of the most important factors

in determining whether a chemical reaction will occur

Page 67: Life Chemistry of

Energy in Reactions- Chemical reactions that release energy often occur

spontaneously

- Energy is released in the form of heat

- This is called an Exothermic (releases heat) reaction

- Energy of the products is lower than the energy of

the reactants

- Example: Combustion

Page 68: Life Chemistry of
Page 69: Life Chemistry of

Energy in Reactions- Chemical reactions that absorb energy will not occur

without a source of energy

- Energy is taken in from the surroundings

- This is called an Endothermic (absorbs heat)

- Energy of the products is higher than energy of the

reactants

- Example: Ice Packs

Page 70: Life Chemistry of
Page 71: Life Chemistry of

What is similar between both reactions?

Page 72: Life Chemistry of

Energy in Reactions- Even chemical reactions that release energy do not

always occur spontaneously

- Let’s think about it

Why aren’t our note pages spontaneously bursting

into flames?

- We need to put IN the energy to get the fire

started, which is called the Activation Energy

Page 73: Life Chemistry of

Energy in Reactions- Activation Energy:

- The energy that is needed to get a reaction started

- Activation energy is a factor in whether the overall

chemical reaction releases energy or absorbs energy.

- REMEMBER:

All chemical reactions require ACTIVATION

ENERGY to get started.

Page 74: Life Chemistry of

Enzymes- Some chemical reactions that make life possible are too

slow or have activation energies that are too high to

make them practical for living tissue. - These chemical reactions are made possible by catalyst

- Catalyst:

- substance that speeds up the rate of a chemical

reaction by lowering the activation energy

Page 75: Life Chemistry of

Enzymes- Enzymes:

- Proteins that act

as biological catalysts

by speeding up

chemical reactions

that take place in cells

Page 76: Life Chemistry of

Enzymes- Enzymes are very specific, generally catalyzing only

one chemical reaction

- Part of an enzyme's name is usually derived from the

reaction it catalyzes- Enzymes provide a site where reactants can be brought

together to react

- This site reduces the energy needed for reaction

Page 77: Life Chemistry of

Enzymes- Substrates:

- reactant of an enzyme-catalyzed reaction

- Active Site:

- site on the enzyme where the substrate binds

- Active Site & Substrate have complementary shapes

and fit together like a lock & key

- Referred to as the Enzyme/Substrate Complex

Page 78: Life Chemistry of

Enzymes- Enzymes are specific and only work with their specific

substrate- Once they bind, they “unlock” the energy in that

substrate to change it into a different product - Example: amylase is an enzyme that breaks down

amylose (compound found in starch)

- Once the reaction is over, the products of the reaction

are released and the enzyme is free to start the process

again

Page 79: Life Chemistry of

Enzymes- Enzymes are not changed during the chemical reaction.

- They can be reused after

- Enzymes are involved in many reactions in human

bodies, such as muscle contractions, metabolism, and

digestion

- Enzymes are also used commercially in products like

detergents to break down stains on clothing

Page 80: Life Chemistry of

Label Enzyme Diagram

Page 81: Life Chemistry of

Label Enzyme Diagram

Page 82: Life Chemistry of

Label Enzyme Diagram

Page 83: Life Chemistry of

Label Enzyme Diagram

Page 84: Life Chemistry of

Regulation of Enzyme Activity - Enzymes can be affected by any variable that

influences a chemical reaction

- Temperature

- pH Levels

- Inhibitors

- Coenzymes

Page 85: Life Chemistry of

Regulation of Enzyme Activity - Temperature:

- Each enzyme has a temperature range in which it is

most effective

- High temperature (too hot) can denature enzyme

(break it apart)

- Low temperature (too cold) can slow down or stop

enzyme activity

Page 86: Life Chemistry of

Regulation of Enzyme Activity - pH:

- Each enzyme has an ideal pH range

- Too acidic or too basic can slow down the

productivity of an enzyme

- Changes in temp & pH cause a DECREASE in product

production

Page 87: Life Chemistry of

Regulation of Enzyme Activity - Competitive Inhibitor:

- A compound that is similar to the substrate

- It binds to the active site & blocks the substrate

- Competitive Inhibitors cause a DECREASE in

product production.

Page 88: Life Chemistry of

Regulation of Enzyme Activity - Coenzyme:

- Enzyme helper

- Compound that helps enzyme & substrate bind

- Coenzymes cause an INCREASE in product

production